1/* asm/bitops.h for Linux/CRIS 2 * 3 * TODO: asm versions if speed is needed 4 * 5 * All bit operations return 0 if the bit was cleared before the 6 * operation and != 0 if it was not. 7 * 8 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). 9 */ 10 11#ifndef _CRIS_BITOPS_H 12#define _CRIS_BITOPS_H 13 14/* Currently this is unsuitable for consumption outside the kernel. */ 15#ifdef __KERNEL__ 16 17#include <asm/arch/bitops.h> 18#include <asm/system.h> 19#include <asm/atomic.h> 20#include <linux/compiler.h> 21 22/* 23 * Some hacks to defeat gcc over-optimizations.. 24 */ 25struct __dummy { unsigned long a[100]; }; 26#define ADDR (*(struct __dummy *) addr) 27#define CONST_ADDR (*(const struct __dummy *) addr) 28 29/* 30 * set_bit - Atomically set a bit in memory 31 * @nr: the bit to set 32 * @addr: the address to start counting from 33 * 34 * This function is atomic and may not be reordered. See __set_bit() 35 * if you do not require the atomic guarantees. 36 * Note that @nr may be almost arbitrarily large; this function is not 37 * restricted to acting on a single-word quantity. 38 */ 39 40#define set_bit(nr, addr) (void)test_and_set_bit(nr, addr) 41 42/* 43 * clear_bit - Clears a bit in memory 44 * @nr: Bit to clear 45 * @addr: Address to start counting from 46 * 47 * clear_bit() is atomic and may not be reordered. However, it does 48 * not contain a memory barrier, so if it is used for locking purposes, 49 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() 50 * in order to ensure changes are visible on other processors. 51 */ 52 53#define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr) 54 55/* 56 * change_bit - Toggle a bit in memory 57 * @nr: Bit to change 58 * @addr: Address to start counting from 59 * 60 * change_bit() is atomic and may not be reordered. 61 * Note that @nr may be almost arbitrarily large; this function is not 62 * restricted to acting on a single-word quantity. 63 */ 64 65#define change_bit(nr, addr) (void)test_and_change_bit(nr, addr) 66 67/** 68 * test_and_set_bit - Set a bit and return its old value 69 * @nr: Bit to set 70 * @addr: Address to count from 71 * 72 * This operation is atomic and cannot be reordered. 73 * It also implies a memory barrier. 74 */ 75 76static inline int test_and_set_bit(int nr, volatile unsigned long *addr) 77{ 78 unsigned int mask, retval; 79 unsigned long flags; 80 unsigned int *adr = (unsigned int *)addr; 81 82 adr += nr >> 5; 83 mask = 1 << (nr & 0x1f); 84 cris_atomic_save(addr, flags); 85 retval = (mask & *adr) != 0; 86 *adr |= mask; 87 cris_atomic_restore(addr, flags); 88 return retval; 89} 90 91/* 92 * clear_bit() doesn't provide any barrier for the compiler. 93 */ 94#define smp_mb__before_clear_bit() barrier() 95#define smp_mb__after_clear_bit() barrier() 96 97/** 98 * test_and_clear_bit - Clear a bit and return its old value 99 * @nr: Bit to clear 100 * @addr: Address to count from 101 * 102 * This operation is atomic and cannot be reordered. 103 * It also implies a memory barrier. 104 */ 105 106static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) 107{ 108 unsigned int mask, retval; 109 unsigned long flags; 110 unsigned int *adr = (unsigned int *)addr; 111 112 adr += nr >> 5; 113 mask = 1 << (nr & 0x1f); 114 cris_atomic_save(addr, flags); 115 retval = (mask & *adr) != 0; 116 *adr &= ~mask; 117 cris_atomic_restore(addr, flags); 118 return retval; 119} 120 121/** 122 * test_and_change_bit - Change a bit and return its old value 123 * @nr: Bit to change 124 * @addr: Address to count from 125 * 126 * This operation is atomic and cannot be reordered. 127 * It also implies a memory barrier. 128 */ 129 130static inline int test_and_change_bit(int nr, volatile unsigned long *addr) 131{ 132 unsigned int mask, retval; 133 unsigned long flags; 134 unsigned int *adr = (unsigned int *)addr; 135 adr += nr >> 5; 136 mask = 1 << (nr & 0x1f); 137 cris_atomic_save(addr, flags); 138 retval = (mask & *adr) != 0; 139 *adr ^= mask; 140 cris_atomic_restore(addr, flags); 141 return retval; 142} 143 144#include <asm-generic/bitops/non-atomic.h> 145 146/* 147 * Since we define it "external", it collides with the built-in 148 * definition, which doesn't have the same semantics. We don't want to 149 * use -fno-builtin, so just hide the name ffs. 150 */ 151#define ffs kernel_ffs 152 153#include <asm-generic/bitops/fls.h> 154#include <asm-generic/bitops/fls64.h> 155#include <asm-generic/bitops/hweight.h> 156#include <asm-generic/bitops/find.h> 157 158#include <asm-generic/bitops/ext2-non-atomic.h> 159 160#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a) 161#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a) 162 163#include <asm-generic/bitops/minix.h> 164#include <asm-generic/bitops/sched.h> 165 166#endif /* __KERNEL__ */ 167 168#endif /* _CRIS_BITOPS_H */ 169